The present invention relates generally to conveyors and, more particularly, to belt conveyors. The present invention also relates generally to angled conveyor sections which are positioned at an angle with respect to a conveyor or transport system to induct or discharge articles onto or off from the conveyor or transport system.
It is known to provide zones of rollers along a roller conveyor, where each zone includes a motorized roller and a plurality of idler or freely rotating rollers. The motorized roller is typically operable to drive the idler rollers via a plurality of O-rings connecting each roller to an adjacent roller in the zone. Each zone may be independently operable to accumulate articles on a particular zone or zones or to generally continuously convey articles along the zones of the roller conveyor. However, such roller conveyors are not suitable for certain applications where belt conveyors are desired, such as for conveying small articles which may fall between the rollers or for applications where a belt conveyor may be required or desired for other reasons. Also, due to the low friction between the rollers and the articles being conveyed thereon, such roller conveyors are not suitable for providing accumulation of articles along an inclined or declined section of the roller conveyor.
Also, it is known to provide an angled discharge junction or connecting conveyor section at a discharge conveyor or station of a sorting system. The discharge junctions typically comprise a plurality of different length rollers rotatably mounted between a sidewall of the junction and an angled mating or connecting frame, such that the rollers are positioned in an ascending length order to define an angled mating edge or connection at the sorting system conveyor or transport path. The rollers are typically freely rotating rollers and function to transport articles from the transport or sorting system to a discharge conveyor or station at the opposite end of the angled junction. Articles are discharged from the transport system and may coast over the different length rollers and onto the discharge conveyor or station. It is also known to provide angled belted conveyor sections where a continuous belt is reeved around rollers and is operable to induct or discharge articles at a main conveying path or transport path. However, such angled belted conveyor sections typically include complicated routing paths for the belt beneath the conveyor section to properly align and track the belt around an end roller at the angled mating edge of the angled belted conveyor section.
The present invention provides a belt conveyor which is suitable for continuously conveying articles along the conveyor or along segments or zones of the conveyor, and/or for accumulating articles on the individual segments or zones, and may provide for accumulation of articles on an incline or a decline.
The present invention provides a belt conveyor which may include a plurality of segments or zones, each of which includes a continuous belt routed around a plurality of rollers. Each of the zones of the conveyor includes a motorized roller and at least one idler roller and may be independently operable to move articles along the belt conveyor or to accumulate articles on one or more of the zones of the belt conveyor. The present invention also provides an angled belt strip roller conveyor section which is positionable at a conveyor or transport path or system, such as a belt conveyor or a roller conveyor, to induct or discharge articles onto or off from the transport system. The angled conveyor section comprises a plurality of different length rollers arranged to define the angled mating end of the angled conveyor section and a plurality of different length belt strips reeved or routed or positioned around the rollers and the motorized roller.
According to an aspect of the present invention, a belt conveyor includes a motorized roller and at least one idler roller positioned along and between opposite sidewalls of the conveyor and a continuous belt reeved around the motorized roller and the idler roller or rollers. The motorized roller is operable to drive the belt around the rollers to move articles along the belt conveyor. The belt has a low modulus characteristic. There may be at least approximately a 0.75% initial stretch to the belt in a lengthwise direction of the belt when the belt is reeved or positioned around the rollers. The low modulus characteristic of the belt may provide approximately a 2% to 4% or more stretch capability or characteristic to the belt.
The belt conveyor may comprise two or more zones, which may be independently operable to allow for accumulation of articles at one or more zones along the belt conveyor. Each zone may include an article sensor, which is operable to detect articles on the belt of the respective zone, whereby the motorized roller of each zone is operable in response to the sensor and the particular application of the segmented belt conveyor.
Optionally, the belt conveyor may be implemented at an incline or a decline, and may be operable to accumulate articles on the incline or decline. Optionally, the belt conveyor may be operable to feed stacks of trays to a tray destacking apparatus at an induct of a tray handling system or tray management system at a mail sortation assembly. It is further envisioned that the belt conveyor may be implemented on an extendable loader or unloader for loading or unloading articles at a trailer or the like. Clearly, the belt conveyor may be implemented in other applications, without affecting the scope of the present invention.
According to another aspect of the present invention, a belt accumulator comprises opposite sidewalls and at least two tandem zones. Each of the tandem zones comprises a motorized roller and at least one idler roller rotatably mounted at and between the opposite sidewalls, a continuous belt reeved around the motorized roller and the at least one idler roller, and at least one article sensor operable to detect articles in that zone. The continuous belt of each of the tandem zones comprises a low modulus characteristic. The belt is initially stretched in a lengthwise direction of the belt at least 0.75% when the belt is reeved around the rollers. The belt accumulator includes at least one control which is operable to control the motorized roller of each zone to drive the belt to convey articles along the respective zone. The control is operable to selectively and independently control the motorized rollers in response to the article sensors to provide accumulation of articles in the zones of the belt accumulator.
According to another aspect of the present invention, a belt conveyor comprises opposite sidewalls, a motorized roller and at least one idler roller rotatably mounted at and between the opposite sidewalls, a continuous belt reeved around the motorized roller and the idler roller or rollers, and at least one article sensor operable to detect articles on the belt. The motorized roller comprises an internal motor operable to rotatably drive a roller portion of the roller relative to an axle portion of the roller. The motorized roller is operable to drive the belt to convey articles along the belt conveyor. The motorized roller is selectively operable in response to the article sensor or sensors.
The belt conveyor may comprise at least two tandem zones. The motorized roller of each of the tandem zones may be operable independently from other motorized rollers of other tandem zones to provide accumulation of articles at one or more of the tandem zones. The motorized roller may be selectively and independently operable in response to an article sensor at each zone to provide accumulation of articles in the zones of the belt conveyor.
The continuous belt may comprise a low modulus characteristic, which provides approximately a 1.5% or more stretch characteristic to the belt, and may provide approximately a 2% or 4% or more stretch characteristic to the belt. The belt may have at least approximately a 0.75% initial stretch in a lengthwise direction of the belt when the belt is reeved or positioned around the rollers.
According to another aspect of the present invention, an angled conveyor section is configured to be positioned along a main transport path to convey articles, which are discharged from the transport path, away from the transport path. The angled conveyor section is positionable at an angle relative to the transport path and comprises opposite sidewalls and an angled frame portion defining an angled mating edge of the angled conveyor for positioning adjacent to a side of the transport path. The angled conveyor section also comprises a plurality of rollers including a motorized roller and a plurality of idler rollers. At least some of the idler rollers have different lengths from the other rollers. A plurality of belt strips are reeved around some of the rollers. The different length rollers are mounted to the angled frame portion and one of the sidewalls and arranged in ascending length order along the angled conveyor to define an angled roller conveying surface. At least some of the belt strips have different lengths from other belt strips and are reeved around the motorized roller and different ones of the different length rollers. The belt strips and the rollers define a belted conveying surface along the angled conveyor section with an angled mating edge positionable adjacent to the transport path.
The motorized roller may be positioned at an end of the angled conveyor section opposite from the angled frame portion. The motorized roller or one or more of the other rollers may include a plurality of tracking devices operable to track the plurality of belt strips on the motorized roller. At least some of the different length rollers may include corresponding tracking devices operable to track respective ones of the plurality of belt strips on the different length rollers. The tracking devices may comprise strips or crowns around the respective rollers.
The belt strips may have a low modulus characteristic and may have at least approximately a 0.75% initial stretch in their lengthwise direction when the belt strips are reeved or positioned around the rollers. The low modulus characteristic of the belt strips may provide approximately a 2% to 4% or more stretch capability or characteristic to the belt strips.
Therefore, the present invention provides a belt conveyor which may have a plurality of independently operable zones or segments, each of which includes a continuous conveyor belt driven by a motorized roller. The zones may operate together as a generally continuously running belt conveyor or may operate individually as an accumulating conveyor with zone control and photo eyes or sensors. The present invention thus provides a zone controlled belt conveyor which may operate in a similar manner as a zone controlled roller conveyor, but with a conveyor belt reeved around the motorized roller and idler rollers rather than with multiple O-rings or the like connecting the idler rollers to the motorized roller of each zone. The belt conveyor of the present invention thus is capable of accumulating articles on an incline or decline. Because the motorized roller of each zone may only control or drive a small belt section or zone, the load and wear on the motorized roller is minimized to provide a longer life cycle for the motorized roller.
The angled conveyor section of the present invention provides a substantially continuous, belted conveying surface at an angle for abutting or mating against a conveying or transport path. The angled conveyor section includes a motorized roller which is operable to drive the different length rollers of the angled conveyor section via a plurality of different length belt strips reeved around the motorized roller and the different length rollers of the conveyor section. The angled conveyor section of the present invention thus provides a powered or motorized roller and a belt conveying surface which does not require special routing of the belt underneath the angled section to align the belt with the angled mating surface or edge.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.